The present invention generally relates to circuit boards, and more particularly relates to bar code apparatus and methods used to provide a user of a circuit board with technical and other identifying information relative to the board subsequent to its manufacture.
To provide a variety of identification and technical information, such as part number, revision, day code, manufacturer, etc. for a circuit board, it is conventional for the board manufacturer to place one or more bar code stickers on a side surface of the board. The theory is that, like a bar-coded grocery item, the circuit board may later be optically scanned to provide, via the bar code sticker, a user subsequently incorporating the board into a product, such as a computer, with a readout of the encoded information.
While this board-identifying technique appears at first glance to be quite simple and straightforward, it is subject to various well known problems, limitations and disadvantages. For example, since the adhesive bar code stickers are separate from the boards that they must subsequently identify, it is possible for one or more incorrect stickers to be applied to a given circuit board. Additionally, relatively large electronic components mounted on the sticker side of the board can "shade" an adjacent bar code sticker from the beam of the scanner used to decipher it, thereby hindering the retrieval of bar code information from the board. Moreover, particularly in very dense circuit board designs such as in notebook computer and pager boards, the use of several bar code stickers on a side surface of the board tends to occupy an undesirably large side surface area that could otherwise be used for additional electronic components, surface traces and the like.
As can readily be seen from the foregoing, it would be highly desirable to incorporate in a circuit board an improved scannable bar code type structure and associated methods that provide desired information about the circuit board while at the same time eliminate or at least substantially reduce the above-mentioned problems, limitations and disadvantages typically associated with conventional side-surface mounted scannable bar code structures as generally described above. It is accordingly an object of the present invention to provide such improved circuit board bar code structure and methods.